Mathjax
$$
z = 2a + 3y
$$
$$
M(s)<M(t)<|M| = m
$$
$$
y'' = c\{f[y',y(x)] + g(x)\}
$$
$$
x^2 \ a_n \ x^n_i
$$
$$
\sum_{i=1}^n \int_a^b
$$
$$
A = \begin{bmatrix}
a_{11} & a_{12} & \cdots & a_{1n}\\
a_{21} & a_{22} & \cdots & a_{2n}\\
\vdots & \vdots & \ddots & \vdots \\
a_{m1} & a_{m2} & \cdots & a_{mn}
\end{bmatrix}
$$
$$
\begin{pmatrix}
a_{11} & a_{12} \\
a_{21} & a_{22}
\end{pmatrix}
\begin{pmatrix}
b_{11} & b_{12} & b_{13}\\
b_{21} & b_{22} & b_{23}
\end{pmatrix}
=
\begin{pmatrix}
a_{11}b_{11}+ a_{12}b_{21} & a_{11}b_{12}+ a_{12}b_{22} & a_{11}b_{13}+ a_{12}b_{23}\\
a_{21}b_{11}+ a_{22}b_{21} & a_{21}b_{12}+ a_{22}b_{22} & a_{21}b_{13}+ a_{22}b_{23}
\end{pmatrix}
$$